5&15. Energetics Flashcards Preview

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Flashcards in 5&15. Energetics Deck (18)
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1
Q

 Temperature =

A

a measure of the average kinetic energy of the particles in a substance.

2
Q

 Specific heat capacity =

A

the energy required to raise the temperature of 1kg of a substance by 1K.

3
Q

 Enthalpy change =

A

the amount of heat evolved or absorbed in a reaction carried out at constant pressure (kJmol-1).

4
Q

 Exothermic reaction =

A

a chemical reaction that releases energy because the energy released forming bonds is greater than the energy required to break the bonds. ΔH<0

5
Q

 Endothermic reaction =

A

a chemical reaction that absorbs energy because the energy released forming bonds is less than the energy required to break the bonds. ΔH>0

6
Q

 Enthalpy change of formation (ΔHf) =

A

the change of enthalpy during the formation of 1 mole of the substance from its constituent elements, with all substances in their standard states, and at a pressure of 1 bar (100 kPa).

7
Q

 Enthalpy change of combustion (ΔHc) = .

A

the enthalpy change when 1 mole of a compound is completely burnt in oxygen gas at 298K and 1 bar pressure

8
Q

 Standard enthalpy of reaction (ΔHr⊖) =

A

the enthalpy change that occurs in a system when matter is transformed by a chemical reaction under standard conditions.

9
Q

 Hess’s law =

A

the enthalpy change for a reaction that is carried out in a series of steps is equal to the sum of the enthalpy changes for the individual steps.

10
Q

 Average bond enthalpy =

A

the energy required to break one mol of a bond in a gaseous molecule averaged over similar compounds.

11
Q

 Bond dissociation energy =

A

the energy required to break one mole of specific bonds in a specific molecule in the gaseous state.

12
Q

 Enthalpy of hydration =

A

the enthalpy change when 1 mole of gaseous ions dissolves in sufficient water to give an infinitely dilute solution.

13
Q

 First ionisation energy =

A

the energy required to remove one mole of the most loosely held electrons from one mole of gaseous atoms to produce 1 mole of gaseous ions each with a charge of 1+.

14
Q

 Enthalpy of atomization =

A

the enthalpy change that accompanies the total separation of all atoms in one mol of a chemical substance.

15
Q

 Electron affinity =

A

the energy change when an electron is added to each of the neutral atoms or molecules in one mol of the substance in the gaseous state to form a negative ion.

16
Q

 Lattice enthalpy =

A

the energy required to break 1 mole of an ionic lattice into its individual constituent ions at infinite separation.

17
Q

 Enthalpy of solution =

A

the enthalpy change associated with the dissolution of a substance in a solvent at constant pressure resulting in infinite dilution.

18
Q

 Entropy (S) =

A

a measure of disorder (JK-1).